A backlight module is used to provide the backlight source of liquid crystal displays (LCDs), which is an indispensable and important display component of LCDs. In the prior art, the backlight source of LEDs of a direct type light emitted diode is replaced from conventional cold cathode fluorescent lamps (CCFLs) to white LEDs, and with respect to the conventional CCFLs, the white LEDs is greener and more efficiency. However, corresponding light source is converted to point light source of white LEDs from linear light source of conventional CCFLs, so that the difficulty of achieving uniformly mixing light becomes greater. Furthermore, white LEDs of the direct type light emitted diode generally apply high-power LEDs to reduce the requirement of cost. Therefore, the amount of LEDs applied becomes less, so as to cause the spacing of the arrangement therebetween LEDs larger, further causing the difficulty of the point light source of uniform mixing light getting larger. Moreover, in the direct type backlight, the high-power white LEDs needs larger thickness of the light casing for avoiding generating the mura of LEDs to completely mix light, so that the thickness of the backlight module is too large to contrary the slim trend of LEDs in the prior art. Here, the backlight phenomenon of irregular luminance generally is termed as “mura”.
As a result, it is necessary to provide a new type backlight module structure to solve the problems that its can not uniformly mix light and the thickness of the light casing is too large, as the foregoing backlight module.